Alternative Transient Program (ATP)

ATP is a universal program system for digital simulation of transient phenomena of electromagnetic as well as electromechanical nature. With this digital program, complex networks and control systems of arbitrary structure can be simulated.

ATP has extensive modelling capabilities and additional important features besides the computation of transients. It has been continuously developed through international contributions over the past 20 years.

Operating Principles

Basically, trapezoidal rule of integration is used to solve the differential equations of system components in the time domain.

Non-zero initial conditions can be determined either automatically by a steady-state, phasor solution or they can be entered by the user for simpler components.

Interfacing capability to the program modules TACS (Transient Analysis of Control Systems) and MODELS (a simulation language) enables modelling of control systems and components with nonlinear characteristics such as arcs and corona.

Symmetric or unsymmetric disturbances are allowed, such as faults, lightning surges, any kind of switching operations including commutation of valves.

Hardware Requirements

Most users, including program developers, use Intel Pentium based PC's with Ms-Windows 3.x/95/NT/XP. A standard PC configuration with 64 MB RAM, hard disk (30 MB free space) and VGA graphics is sufficient to execute ATP under MS-DOS/MS-Windows. ATP is available for other computers, too.

Maximum Capabilities

ATP-EMTP tables are dimensioned dynamically at the start of execution to satisfy the needs of users and their hardware (e.g., RAM). No absolute limits have ever been observed, and the standard version has limits that average more than 20 times default table sizes. Today, the largest simulations are being performed using MS-DOS computers.

Default table sizes:

Busses

3000

Branches

3000

Switches

1200

Sources

340

Nonlinear elements

460

Synchronous machines

45

Additional Tools

ATPDraw for Windows

ATPDRAW is a graphical, mouse-driven preprocessor for ATP on the MS-Windows 9x/NT/XP platforms. Using ATPDraw for Windows, one builds a graphical picture of an electric circuit by picking objects from menus, connecting and editing objects, and keying data interactively. ATPDRAW then creates the corresponding ATP input data file. The user can create his own circuit objects by using the Data Base Module feature of ATP.

About Us

This site has been established for the users of the royalty-free ATP version of the Electromagnetic Transients Program (EMTP). The ATP license is free for nearly everyone accepting the rules expressed in written form when filling the license form.

The site is maintained by the Europan EMTP-ATP users group. There are other related web-sites: